. "HPB"@en . "Hilton Plant Beds"@en . . . "stable"@en . "251.9"^^ . . "Stratified bedrock. Occurs onshore. Deposited during the Guadalupian Epoch - to - Lopingian Epoch (Permian Period) (274.4-251.9 Ma BP)."@en . . . "Hilton Plant Beds"@en . "274.4"^^ .